|Scientific Name:||Mesoplodon ginkgodens|
|Species Authority:||Nishiwaki & Kamiya, 1958|
Mesoplodon hotaula Deraniyagala, 1963
|Red List Category & Criteria:||Data Deficient ver 3.1|
|Assessor/s:||Taylor, B.L., Baird, R., Barlow, J., Dawson, S.M., Ford, J., Mead, J.G., Notarbartolo di Sciara, G., Wade, P. & Pitman, R.L.|
|Reviewer/s:||Hammond, P.S. & Perrin, W.F. (Cetacean Red List Authority)|
There is no information on abundance or trends in global abundance for this species. As a relatively uncommon species it is potentially vulnerable to low-level threats and a 30% global reduction over three generations cannot be ruled out (criterion A).
|Range Description:||The ginkgo-toothed beaked whale is known from only a few dozen widely-scattered strandings and captures (no confirmed sightings) in temperate and tropical waters of the Indo-Pacific Ocean, from Sri Lanka east to the shores of North America (California) and the Galápagos Islands (Mead 1989; Pitman 2002). There have been a few records from New Zealand and Australia, indicating that this species also inhabits the southern Indo-Pacific. Most records are from the seas around Japan. Sightings of what may have been this species were also made in the Arabian Sea. It is generally hypothesized that the range is continuous across the Pacific and at least to the eastern Indian Ocean, but until the species can be reliably identified at sea, its true distribution will probably remain unknown (MacLeod et al. 2006).|
Native:American Samoa (American Samoa); Australia (New South Wales, Northern Territory, Queensland, South Australia, Tasmania, Western Australia); Chile; China; Colombia; Cook Islands; Ecuador (Galápagos); Fiji; French Polynesia; India; Indonesia; Japan; Kenya; Kiribati; Marshall Islands; Mexico (Baja California Sur, Guadalupe I., Revillagigedo Is.); Micronesia, Federated States of ; Nauru; New Caledonia; New Zealand (Chatham Is., North Is.); Niue; Northern Mariana Islands; Palau; Papua New Guinea; Peru; Philippines; Pitcairn; Samoa; Sri Lanka; Taiwan, Province of China; Tanzania, United Republic of; Tokelau; Tonga; Tuvalu; United States (California, Hawaiian Is.); United States Minor Outlying Islands (Howland-Baker Is., Midway Is., US Line Is., Wake Is.); Vanuatu; Wallis and Futuna
|FAO Marine Fishing Areas:||
Indian Ocean – eastern; Indian Ocean – western; Pacific – eastern central; Pacific – northwest; Pacific – southwest; Pacific – western central
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||There are no estimates of abundance, but the species does not appear to be very common anywhere. There is no information on trends in the global abundance of this species.|
|Habitat and Ecology:||
Ginkgo-toothed whales are found in the tropical and warm temperate waters of the Indo-Pacific. Like other species in the genus, ginkgo-toothed beaked whales are thought to occur primarily in deep, offshore waters.
These whales are presumed to be primarily squid eaters but may also take some fish.
Ginkgo-toothed beaked whales have occasionally been taken by Japanese and Taiwanese whalers, and some have been caught in deepwater drift gillnets.
This species, like other beaked whales, is likely to be vulnerable to loud anthropogenic sounds, such as those generated by navy sonar and seismic exploration (Cox et al. 2006). The use of active sonar from military vessels has been implicated in mass strandings of ginkgo-toothed beaked whales (Wang and Yang 2006; Yang et al. 2008).
Evidence from stranded individuals of several similar species indicates that they have swallowed discarded plastic items, which may eventually lead to death (e.g. Scott et al. 2001); this species may also be at risk.
Predicted impacts of global climate change on the marine environment may affect this species of whale, although the nature of impacts is unclear (Learmonth et al. 2006).
|Conservation Actions:||The species is listed in Appendix II of CITES. Research is needed to determine the impacts of potential threatening processes on this species.|
Anderson, R. C. 2005. Observations of cetaceans in the Maldives, 1990-2002. Journal of Cetacean Research and Management 7(2): 119-135.
Balcomb, K. C. and Claridge, D. E. 2001. A mass stranding of cetaceans caused by naval sonar in the Bahamas. Bahamas Journal of Science 8(2): 2-12.
Barlow, J. 1999. Trackline detection probability for long-diving whales. In: G. W. Garner, S. C. Amstrup, J. L. Laake, B. J. F. Manley, L. L. McDonald and D. G. Robertson (eds), Marine mammal survey and assessment methods, pp. 209-221. Balkema Press, Netherlands.
Cox, T. M., Ragen, T. J., Read, A. J., Vos, E., Baird, R. W., Balcomb, K., Barlow, J., Caldwell, J., Cranford, T., Crum, L., D'Amico, A., D'Spain, A., Fernández, J., Finneran, J., Gentry, R., Gerth, W., Gulland, F., Hildebrand, J., Houser, D., Hullar, T., Jepson, P. D., Ketten, D., Macleod, C. D., Miller, P., Moore, S., Mountain, D., Palka, D., Ponganis, P., Rommel, S., Rowles, T., Taylor, B., Tyack, P., Wartzok, D., Gisiner, R., Mead, J. and Benner, L. 2006. Understanding the impacts of anthropogenic sound on beaked whales. Journal of Cetacean Research and Management 7(3): 177-187.
Fernández, A., Edwards, J. F., Rodriguez, F., Espinosa, A., De Los Monteros, Herraez, P., Castro, P., Jaber, J. R., Martin, V. and Arebelo, M. 2005. "Gas and fat embolic syndrome" involving a mass stranding of beaked whales (family Ziphiidae) exposed to anthropogenic sonar signals. Veterinary Pathology 42: 446-457.
Gomercic, H., Gomercic, M. D., Gomericic, T., Lucic, H., Dalebout, M., Galov, A., Skrtic, D., Curkovic, S., Vukovic, S. and Huber, D. 2006. Biological aspects of Cuvier's beaked whale (Ziphius cavirostris) recorded in the Croatian part of the Adriatic Sea. European Journal of Wildlife Research 52(3): 182-187.
IUCN. 2008. 2008 IUCN Red List of Threatened Species. Available at: http://www.iucnredlist.org. (Accessed: 5 October 2008).
Jepson, P. D., Arebelo, M., Deaville, R., Patterson, I. A. P., Castro, P., Baker, J. R., Degollada, E., Ross, H. M., Herraez, P., Pocknell, A. M., Rodriguez, F., Howie, F. E., Espinosa, A., Reid, R. J., Jaber, J. R., Martin, V., Cunningham, A. A. and Fernandez, A. 2003. Gas-bubble lesions in stranded cetaceans. Nature 425: 575-576.
Learmonth, J. A., Macleod, C. D., Santos, M. B., Pierce, G. J., Crick, H. Q. P. and Robinson, R. A. 2006. Potential effects of climate change on marine mammals. Oceanography and Marine Biology: An Annual Review 44: 431-464.
Macleod, C. D., Perrin, W. F., Pitman, R. L., Barlow, J., Balance, L., D'amico, A., Gerrodette, T., Joyce, G., Mullin, K. D., Palka, D. L. and Waring, G. T. 2006. Known and inferred distributions of beaked whale species (Ziphiidae: Cetacea). Journal of Cetacean Research and Management 7(3): 271-286.
Malakoff, D. 2002. Suit ties whale deaths to research cruise. Science 298: 722-723.
Mead, J. G. 1989. Beaked whales of the genus Mesoplodon. In: S. H. Ridgway and R. Harrison (eds), Handbook of marine mammals, Vol. 4: River dolphins and the larger toothed whales, pp. 349-430. Academic Press.
Pitman, R. L. 2002. Mesoplodont whales Mesoplodon spp. In: W. F. Perrin, B. Wursig and J. G. M. Thewissen (eds), Encyclopedia of Marine Mammals, pp. 738-742. Academic Press.
Scott, M. D., Hohn, A. A., Westgate, A. J., Nicolas, J. R., Whitaker, B. R. and Campbell, W. B. 2001. A note on the release and tracking of a rehabilitated pygmy sperm whale (Kogia breviceps). Journal of Cetacean Research and Management 3(1): 87-94.
Wang, J. Y. and Yang, S. C. 2006. Unusual cetacean stranding events of Taiwan in 2004 and 2005. Journal of Cetacean Research and Management 8: 283-292.
Yang, W.-C., Chou, L.-S., Jepson, P. D., Brownell Jr., R. L., Cowan, D., Chang, P.-H., Chiou, H.-I., Yao, C.-J., Yamada, T. K., Chiu, J.-T., Wang, P.-J. and Fernandez, A. 2008. Unusual cetacean mortality events in Taiwan, possibly linked to naval activities. Veterinary Record 162: 184-186.
|Citation:||Taylor, B.L., Baird, R., Barlow, J., Dawson, S.M., Ford, J., Mead, J.G., Notarbartolo di Sciara, G., Wade, P. & Pitman, R.L. 2008. Mesoplodon ginkgodens. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <www.iucnredlist.org>. Downloaded on 24 April 2014.|